<?php
//参考：http://blog.csdn.net/kylinbl/article/details/8155382
//验证码类
class ValidateCode
{
    private $charset = '0123456789'; //随机因子
    private $code; //验证码
    private $codelen = 4; //验证码长度
    private $width = 80; //宽度
    private $height = 50; //高度
    private $img; //图形资源句柄
    private $font; //指定的字体
    private $density = 0.8; //文字与文字间隔密度
    private $fontsize = 20; //指定字体大小
    private $fontcolor = "#0404f8"; //指定字体颜色
    

    //构造方法初始化
    public function __construct()
    {
        $this->font = './static/public/font/msyh.ttf'; //注意字体路径要写对，否则显示不了图片
    }
    
    //生成随机码
    private function createCode()
    {
        $_len = strlen($this->charset) - 1;
        for ($i = 0; $i < $this->codelen; $i ++) {
            $this->code .= $this->charset[mt_rand(0, $_len)];
        }
    }
    
    //生成背景
    private function createBg()
    {
        $this->img = imagecreatetruecolor($this->width, $this->height);
        /*背景颜色*/
        /*
        $red = mt_rand(157, 255);
        $green = mt_rand(157, 255);
        $blue = mt_rand(157, 255);*/
        $red = 255;
        $green = 255;
        $blue = 255;
        $color = imagecolorallocate($this->img, $red, $green, $blue);
        imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
    }
    
    //生成文字
    private function createFont()
    {
        $_x = $this->width / $this->codelen;
        $red = 4;
        $green = 4;
        $blue = 255;
        for ($i = 0; $i < $this->codelen; $i ++) {
            $this->fontcolor = imagecolorallocate($this->img, $red, $green, $blue);
          
            imagettftext($this->img, $this->fontsize, mt_rand(- 30, 30), $_x * $i * $this->density, $this->height / 1.4, $this->fontcolor, $this->font, $this->code[$i]);
        }
    }
    
    //生成线条、雪花  默认 线条6 雪花100
    private function createLine()
    {
        //线条
        for ($i = 0; $i < 2; $i ++) {
            $color = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
            imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
        }
        
        //雪花
        for ($i = 0; $i < 5; $i ++) {
            $color = imagecolorallocate($this->img, mt_rand(200, 255), mt_rand(200, 255), mt_rand(200, 255));
            imagestring($this->img, mt_rand(1, 5), mt_rand(0, $this->width), mt_rand(0, $this->height), '*', $color);
        }
       
    
    }
    
    //输出
    private function outPut()
    {
        header('Content-type:image/png');
        imagepng($this->img);
        imagedestroy($this->img);
    }
    
    //对外生成
    public function doimg()
    {
        $this->createBg();
        $this->createCode();
        $this->createLine();
        $this->createFont();
        $this->outPut();
    }
    
    //获取验证码
    public function getCode()
    {
        return strtolower($this->code);
    }

}